AOS Delete

[BYprodriver]

Originally Posted by whitecliffs

As anyone deleted there AOS, ie blanked off the throttle body and run a pipe from the top of the AOS to a catchment tank/can.

l replaced my startermotor a few weeks ago and found a fair bit of oil in the pipe
between the throttle body and AOS, but i wasn't getting any smoke bombs while
running just the odd puff of blue smoke if reved hard at standstill and when the wife
followed me it did smoke a little but nothing major

Anyway clean out the pipework fitted a new AOS done 300 miles just checked
the pipe and there oil in there again.

Have seen posts on here where a guy had 3 duff one's straight from the box think
it was one of jake's post.

So has anyone deleted theres, if so has there been any performance loss
with the crankcase not being under vacuum

The low tension piston rings rely on the crankcase vacuum to help seal the rings, eliminating that vacuum increases blow-by. If the AOS is disconnected from the vacuum source no oil will come out the top of the AOS.

[JFP in PA]

Originally Posted by BYprodriver

The low tension piston rings rely on the crankcase vacuum to help seal the rings, eliminating that vacuum increases blow-by. If the AOS is disconnected from the vacuum source no oil will come out the top of the AOS.

Along with blow by and he loss of effectiveness for the low tension rings used in these engines, not having vacuum in the case sump will lead to increased water and fuel level build up in the oil as the low vacuum level created by the AOS helps to flash them off at lower temperatures. This will very quickly degrade any oil.